Vitamin E and C supplementation reduces oxidative stress, improves antioxidant enzymes and positive muscle work in chronically loaded muscles of aged rats

Abstract

Aging is associated with increased oxidative stress. Muscle levels of oxidative stress are further elevated with exercise. The purpose of this study was to determine if dietary antioxidant supplementation would improve muscle function and cellular markers of oxidative stress in response to chronic repetitive loading in aging. The dorsiflexors of the left limb of aged and young adult Fischer 344 Brown x Norway rats were loaded 3 times weekly for 4.5 weeks using 80 maximal stretch-shortening contractions per session. The contralateral limb served as the intraanimal control. The rats were randomly assigned to a diet supplemented with Vitamin E and Vitamin C or normal non-supplemented rat chow. Biomarkers of oxidative stress were measured in the tibialis anterior muscle. Repetitive loading exercise increased maximal isometric force, negative and positive work in the dorsiflexors of young adult rats. Only positive work increased in the aged animals that were supplemented with Vitamin E and C. Markers of oxidative stress (H 2 O 2, total GSH, GSH/GSSG ratio, malondialdehyde and 8-OHdG) increased in the tibialis anterior muscles from aged and young adult animals with repetitive loading, but Vitamin E and C supplements attenuated this increase. MnSOD activity increased with supplementation in the young adult animals. CuZnSOD and catalase activity increased with supplementation in young adult and aged animals and GPx activity increased with exercise in the non-supplemented young adult and aged animals. The increased levels of endogenous antioxidant enzymes after Vitamin E and C supplementation appear to be regulated by post-transcriptional modifications that are affected differently by age, exercise, and supplementation. These data suggest that antioxidant supplementation improves indices of oxidative stress associated with repetitive loading exercise and aging and improve the positive work output of muscles in aged rodents.

Type 5 adenylyl cyclase disruption leads to enhanced exercise performance

“…Protection against oxidative stress is often linked with improved exercise tolerance (Nishiyama et al ., 1998; Fisher‐Wellman et al ., 2009; Ryan et al ., 2010). Paraquat, which increases oxidative stress, reduced WT exercise capacity by 40%, and significantly less, P < 0.05 , that is, by only 7% in AC5 KO (Fig.…”

“…As enhanced exercise can result from mechanisms originating in either the heart or skeletal muscle, we examined cardiac and muscle function and also utilized tissue‐specific KOs in the heart and skeletal muscle. Skeletal muscle mitochondrial function (Yamamoto et al ., 2011), mitochondrial biogenesis (Irrcher et al ., 2003), and resistance to oxidative stress (Nishiyama et al ., 1998; Fisher‐Wellman et al ., 2009; Ryan et al ., 2010) were also examined, as these mechanisms mediate exercise performance (Rockl et al ., 2007). The SIRT1, FOXO3a, and MEK pathways, key to mitochondrial biogenesis and protection against oxidative stress, were also examined (Wu et al ., 1999; Lagouge et al ., 2006; Gurd et al ., 2009; Menzies et al ., 2013; Li et al ., 2015; Smith et al ., 2015).…”

Ascorbic Acid and Performance: A Review

“…Vitamin C supplementation (20 g / kg body weight/day) and vitamin E (30 g kg body weight /day) supplemented started one week before the first session of electrical stimulation. In summary, the supplemental vitamin C and E resulted in reduction of the oxidative stress induced by electrical stimulation and concentric work better in old rats, but not in young rats [24].…”

Effects of the combined administration of vitamins C and E on the oxidative stress status and programmed cell death pathways after experimental spinal cord injury

“…21 VCE supplementation also reduces oxidative stress and improves antioxidant enzymes and positive muscle work in chronically loaded muscles of aged rats. 22 In the literature review, combined use of VCE in different SCI studies result in different functional outcomes. Cristante et al, 14 did not find any functional improvements in their animals after the combined use of VCE.…”